A two-tier location management mechanism for IMS

This paper proposed a two-tier location management mechanism （TTLM） by improving the current registration mechanism （CR） in IP Multimedia Subsystem （IMS）. The TTLM includes the visited network registration and the home network registration, in which the visited network registration is responsible for re-registration in IMS. When subscriber roams, the location information of home network will be updated by the visited network based on the change of user equipment （UE）＇ s IP address. Thereibre the TTLM can reduce the times of IMS registration signaling. Using the proposed analytical model, the performance of the CR and the proposed TTLM were investigated. After the performance analysis of CR and TTLM by using proposed analytical model, the cost of CR in IMS could significantly be reduced theoretically and also was proven by simulation experiments.

A Novel Location Management Scheme based on DNS in Proxy Mobile IPv6

Proxy Mobile IPv6 (PMIPv6) is designed to provide a network-based localized mobility management protocol, but it does not handle the global mobility of hosts. In this paper, we propose a location management scheme based on Domain Name System (DNS) for PMIPv6 which can support global mobility by using DNS as a location manager. In addition, to support large numbers of mobile terminals and enhance network scalability a paging extension scheme is introduced to PMIPv6. To evaluate the proposed location management scheme, we establish an analytical model, formulate the location update cost and the paging cost, and analyze the influence of the different factors on the total signaling cost. The performance results show that our proposed scheme outperforms the basic PMIPv6 under various parameters in terms of reducing the signaling overhead and the proposed scheme reduces signaling overhead compared to the basic PMIPv6.

A State-Based Dynamic Location Management Scheme

We consider a state-based dynamic location management scheme, in which, the user is partitioned into different mobility state set. And its location area size is changed dynamically corresponding to the state set that it belongs to. Comparing with the fixed LA scheme, numerical experiment result shows it's performance can be improved by 30% while the current location and paging procedure can still be applied. Besides, as this scheme need not process complicated user information, the requirement of computing power decreases significantly than the user-based schemes. Our scheme can be used in current 2G mobile systems (such as GSM, CDMA) and the third generation (3G) mobile systems with slightly modifying of the equipment software.

A Mobility Management Solution Based on ID/Locator Separation

Current mobility management solutions based on ID/Locator separation are not easily deployed and cannot solve routing scalability and mobility problems. This paper proposes a novel network architecture based on ID/Locator separation and suggests a new mobility management solution. This solution solves the problem of scalability in the network and also provides better support for mobility. It can be easily deployed because no modification of the mobile host’s protocol stack is required. The identifier contains some routing information; so the solution provides intrinsic interworking with traditional mobile hosts. Because the mapping systems are distributed to the edge networks, robustness of the whole system is enhanced and handover delay is decreased.

VSS BASED SESSION SETUP MECHANISM IN IMS

This paper proposes a novel session setup mechanism in IMS(IP Multimedia Subsystem) by introducing the functional entity termed VSS(Visitor Subscriber Server) which is used to provide registration and location management.The new mechanism aims at improving session setup procedure by a betterment of location management in IMS.Through the use of two-tier subscriber information database constituted by the HSS(Home Subscriber Server) and the VSS, the new mechanism seperates the registration procedure and location management from the S-CSCF(Serving-Call'Session Control Function), and makes them be handled by the VSS.At the same time, the new mechanism updates the signaling procedure of registration and session setup.With VSS based location management, the cost of registeration and session setup procedure as well as the delay of session setup procedure become lower.The cost and delay functions of the new session setup mechanism as well as the cost function of new registeration are deduced.Then, simulations and analysis verify that the performance of this new mechanism gets the benefit in cost and time.

Dynamic movement-based location update in LEO networks

Mobility management is an important aspect of the LEO systems. In terrestrial wireless network, the movement of the user triggers the location updating and determines the paging scheme, while in LEO satellite systems, the location updating and paging is mainly based on the movement of satellite. Terrestrial location management techniques must be altered to fit LEO systems. This paper introduces a modified movement based location update and paging scheme in LEO networks. In this scheme we propose the meta cell concept, which includes two spot beams of one satellite. First we present the location management scheme based on the architecture with meta cell location area. Then an analytical model is applied to formulate the cost of location updating and location paging for the and movement meta cell based dynamic location update scheme. The comparison of performance between meta cell architecture method and conventional signal spot cell architecture method is provided to demonstrate the cost effectiveness and robust of the proposed scheme under various parameters. To reduce the impact of meta cell architecture on location paging cost, we present forced location update strategy which used in the cases that the meta cell includes the two spot beams from different satellites.

An aggressive location restoration proposal based on pointer

A proposal for smooth aggressive location restoration by forwarding pointer is given in this paper. A mobile communication system＇s robustness in case of a location-database failure is improved without the need for periodic location update operations. Radio resources would be saved at the cost of wire signal and operation of location databases. Meanwhile, a chain of forwarding location pointers has been used during the period of HLR failure. So mobile stations are unconscious of the failure of HLR, and mobile subscribers can always make outgoing call.

A Distributed and Adaptive Location Management Scheme for Hierarchical Mobility Management

Hierarchical mobility management is sensitive to the failure of gateway mobility agents and prone to degrade performance on heavy loads. This paper proposes a distributed and adaptive location management scheme based on Hierarchical Mobile IPv6. This scheme can balance the loads of mobility anchor points and increase the robustness of the hierarchical structure to certain extents. In this scheme, the optimized IP paging scheme is adopted to reduce the paging signaling cost and improve the scalability of the hierarchical mobility management. We implement the distributed and adaptive location management scheme in a simulation platform and compare its performance with that of two other location management schemes. Our simulation results show that our scheme is capable of balancing the signaling and traffic loads of mobility ancher points, decreasing the average handover latency, and increasing the throughout of the visited networks.

An IP mobility management scheme with dual location areas for IP/LEO satellite network

One of the issues of mobility management in a low Earth orbit (LEO) satellite network is the high-frequency location binding update initiated by mobile nodes (MNs).To solve this problem,we propose a location management scheme based on dual location area (LA) in an IP/LEO satellite network.The proposed scheme uses two kinds of LA,the fixed Earth station LA and satellite LA,to manage the location of the MNs together.MNs operate the binding update procedures only when they are moving out of both of the two LAs last registered.Geographical location information of MN is used in the binding update procedures,so that the network can page the idle MNs near their last registered location first,to enhance the probability of paging success.A detailed description of the implementation of the scheme is provided.Mathematical analysis shows that the proposed scheme reduces the location management cost and minimizes the influences of the distance between MN and its home agent.Paging cost is also reduced by introducing geographical location information in the binding update procedures.

A distributed location management strategy for next- generation IP-based wireless networks

Location management is the most important function in mobility management technology. The hierarchical structure of the proposed hierarchical network-layer mobility management （HNMM） can reduce the signaling cost. The selforganizing topology scheme can enhance the robustness and quality of the mobility management. The information of location of the mobile node is stored in the distributed database, which makes the storage of the location information more reliable and robust, and more flexible strategies can be used. The numeric results show that HNMM can provide better performance than the general structure of mobile IPv6, when the mobile nodes move frequently and when there is high traffic throughput.

Difference-less mobility management network

Core systemtechnology is a key factor in the next generation network(NGN).Adifference-less mobility management network is proposed to better support the mobility of an IP multimedia subsystem(IMS).This kind of network can provide good service and user mobility,enabling local user access to the network anywhere.User location management and session creation are analyzed.The results show that under this network architecture,the cost of the user location registration and session creation is lower than that of the home control model employed by the IMS.

A General Probability Formula of the Number of Location Areas＇ Boundaries Crossed by a Mobile Between Two Successive Call Arrivals

Mobility management is a challenging topic in mobile computing environment.Studying the situation of mobiles crossing the boundaries of location areas is significant forevaluating the costs and performances of various location management strategies. Hitherto, severalformulae were derived to describe the probability of the number of location areas' boundariescrossed by a mobile. Some of them were widely used in analyzing the costs and performances ofmobility management strategies. Utilizing the density evolution method of vector Markov processes,we propose a general probability formula of the number of location areas' boundaries crossed by amobile between two successive calls. Fortunately, several widely-used formulae are special cases ofthe proposed formula.